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| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2019-12-18 11:30:12 +0000 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2020-01-13 14:05:46 +0100 |
| commit | 394642a8d3742c885e397d5bb5ee0ec40743cdc6 (patch) | |
| tree | ec6b5ea99341cffe2fc1fdd72cb9cacbd36dab94 /hw/arm/stm32f405_soc.c | |
| parent | 32187f3d902afdfa9f4d861d9612739d3391fdc3 (diff) | |
| download | focaccia-qemu-394642a8d3742c885e397d5bb5ee0ec40743cdc6.tar.gz focaccia-qemu-394642a8d3742c885e397d5bb5ee0ec40743cdc6.zip | |
usbredir: Prevent recursion in usbredir_write
I've got a case where usbredir_write manages to call back into itself via spice; this patch causes the recursion to fail (0 bytes) the write; this seems to avoid the deadlock I was previously seeing. I can't say I fully understand the interaction of usbredir and spice; but there are a few similar guards in spice and usbredir to catch other cases especially onces also related to spice_server_char_device_wakeup This case seems to be triggered by repeated migration+repeated reconnection of the viewer; but my debugging suggests the migration finished before this hits. The backtrace of the hang looks like: reds_handle_ticket reds_handle_other_links reds_channel_do_link red_channel_connect spicevmc_connect usbredir_create_parser usbredirparser_do_write usbredir_write qemu_chr_fe_write qemu_chr_write qemu_chr_write_buffer spice_chr_write spice_server_char_device_wakeup red_char_device_wakeup red_char_device_write_to_device vmc_write usbredirparser_do_write usbredir_write qemu_chr_fe_write qemu_chr_write qemu_chr_write_buffer qemu_mutex_lock_impl and we fail as we lang through qemu_chr_write_buffer's lock twice. Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1752320 Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20191218113012.13331-1-dgilbert@redhat.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/arm/stm32f405_soc.c')
0 files changed, 0 insertions, 0 deletions